全文获取类型
收费全文 | 806篇 |
免费 | 33篇 |
出版年
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 15篇 |
2018年 | 32篇 |
2017年 | 36篇 |
2016年 | 36篇 |
2015年 | 24篇 |
2014年 | 16篇 |
2013年 | 228篇 |
2012年 | 21篇 |
2011年 | 19篇 |
2010年 | 24篇 |
2009年 | 17篇 |
2008年 | 21篇 |
2007年 | 16篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 18篇 |
2003年 | 17篇 |
2002年 | 14篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 8篇 |
1998年 | 17篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1986年 | 3篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 5篇 |
1975年 | 9篇 |
1974年 | 3篇 |
1971年 | 6篇 |
1969年 | 4篇 |
排序方式: 共有839条查询结果,搜索用时 15 毫秒
101.
102.
103.
Alan J. Fletcher 《Irish Studies Review》2005,13(2):203-220
104.
When citizens are presented with alternative policy solutions to a given social problem, why do they choose to support one over another? In this article, the authors analyze a survey of residents of the five largest U.S. metropolitan areas to understand determinants of public support for spending on three major components of American drug control policy: law enforcement programs, rehabilitative services for addicts, and school‐based prevention programs. The authors estimate effects of self‐interest, political socialization, and policy attitudes on support for total drug control expenditures and on preferences for each drug control alternative versus the others. Effects of group self‐interest, societal interest, and political socialization change dramatically across dimensions of support. Policy attitudes are strong predictors of both types of support, whereas individual self‐interest measures are not associated with either dimension. 相似文献
105.
106.
107.
108.
109.
The global war on terror was used by the Bush administration and its allies to defend a US dominated geopolitical configuration. To this end, counter‐terrorism measures (CTMs) were introduced which strengthened the alignment of development aid with diplomacy and defence. The broad, adverse effects of CTMs on civil liberties and human rights are well documented. Despite the advent of a new US administration and a ‘soft power’ approach to international relations, the legacy of the war on terror remains embedded in the laws, policies and attitudes of many states and regimes that continue to enclose the lives of citizens. This article describes the experiences of civil society organizations (CSOs) as ‘securitization’ processes unfolded. Studies over two years involving some forty countries provide an on‐the‐ground view to probe the gains and losses of securitization, both for governments in the US‐led ‘coalition of the willing’ and for civil society in terms of the pressures emerging from a development‐for‐security agenda. The authors identify some of the perverse zero‐sum effects on governments of CTM philosophy and the means employed. Findings also show asymmetry between northern and southern CSOs in terms of their negative‐sum subordination, found in the definition of security and in the vulnerability to new risks involved in undertaking development work. 相似文献
110.
Mohan R. Akella Eric Delmelle Rajan Batta Peter Rogerson Alan Blatt 《Geographical analysis》2010,42(3):227-244
In this article, we address the problem of allocating an additional cell tower (or a set of towers) to an existing cellular network, maximizing the call completion probability. Our approach is derived from the adaptive spatial sampling problem using kriging, capitalizing on spatial correlation between cell phone signal strength data points and accounting for terrain morphology. Cell phone demand is reflected by population counts in the form of weights. The objective function, which is the weighted call completion probability, is highly nonlinear and complex (nondifferentiable and discontinuous). Sequential and simultaneous discrete optimization techniques are presented, and heuristics such as simulated annealing and Nelder–Mead are suggested to solve our problem. The adaptive spatial sampling problem is defined and related to the additional facility location problem. The approach is illustrated using data on cell phone call completion probability in a rural region of Erie County in western New York, and accounts for terrain variation using a line‐of‐sight approach. Finally, the computational results of sequential and simultaneous approaches are compared. Our model is also applicable to other facility location problems that aim to minimize the uncertainty associated with a customer visiting a new facility that has been added to an existing set of facilities. 相似文献